About the Author
Barbara Schuetze is a Portland, Ore., freelance writer who specializes in health and wellness topics. She has written for most of the major health systems in Oregon and Southwest Washington, and her work has appeared in magazines, newspapers and on the Web. She has been writing professionally since 1983.
More than three million Americans have glaucoma, but experts estimate that half of them don't know that they have it. And yet, early detection and treatment of glaucoma--before it causes major vision loss--is the best way to control the disease, according to the&nbsp; &nbsp;(NEI).
"The number one risk for blindness is not getting an eye exam," cautions Steven L. Mansberger, MD, MPH, director of clinical trials, Devers Eye Institute at Legacy Health System.
Learning more about glaucoma and understanding how it's detected and treated, can help you guard against potential vision loss and blindness.
What Is Glaucoma?Glaucoma is a group of eye diseases that can cause damage to your optic nerve, the part of your eye that transmits visual images to your brain. If glaucoma goes undetected, or is left untreated, it will lead to a gradual loss of peripheral vision and, ultimately, blindness.
Glaucoma is often, but not always, associated with pressure inside your eye (intraocular pressure) that increases to a level that is too high for the health of your eye. Intraocular pressure depends on a balance between the rate of fluid production in the eye and the rate of outflow. In most cases, increased pressure results from blockage of fluid outflow. "We don't have a clear understanding of what causes glaucoma," says John Morrison, MD, director of Glaucoma Services, Casey Eye Institute at Oregon Health & Science University. "Many labs, including mine, are trying to understand how increased intraocular pressure damages the optic nerve so that we can develop new, more effective treatments for glaucoma."
Most Common Form of Glaucoma Primary open-angle glaucoma is the most common type of glaucoma in the U.S., affecting 80-90 percent of those with the disease. In its early stages, there are virtually no symptoms and usually no pain.
"Glaucoma is known as the sneak thief of sight," explains Dr. Mansberger. "Because it affects your peripheral vision, you don't notice it until the disease has progressed very far, stealing your sight until it seems as if you're seeing things through a keyhole."
Who's at Risk? Everyone is at risk for glaucoma. But you are more likely to get glaucoma if you:
- Are age 60 or older
- Are African American (if so, you have a greater risk of getting glaucoma at a younger age)
- Have a family history of glaucoma or a close relative with glaucoma (parents or siblings)
- Have a history of high intraocular pressure
Other factors that put people at increased risk include: severe nearsightedness, health conditions such as diabetes, steroid use and eye injuries.
How Is It Diagnosed? The National Eye Institute advises patients in high-risk groups to have a dilated eye exam every two years. Some eye professionals recommend exams at different intervals. Check with your doctor to find out when and how often you should have a comprehensive eye exam.
But don't put off that trip to the eye doctor! Damage to your optic nerve and/or blindness due to glaucoma cannot be reversed. Getting treatment immediately for early stage, open-angle glaucoma can delay the progression of the disease. With the proper treatment you can help preserve your sight.
Getting checked for glaucoma is easy and painless. Doctors use a number of diagnostic tools, including:
- A visual acuity test--that good old eye chart test you've had since grade school.
- Pupil dilation for closer examination of your eye.
- A visual field test to measure peripheral vision.
- Tonometry--a test to measure fluid pressure inside your eye.
"Because about fifty percent of people with glaucoma may not have elevated pressure, it's very important for doctors to examine the optic nerve as well as check eye pressure," explains Dr. Morrison. "The key is to look at the optic disk for characteristic signs of glaucomatous damage."How Is It treated? Although glaucoma can't be cured, it can be treated and controlled. In the U.S., the first line of treatment is medication--generally eye drops. "Four main classes of medication are primarily used now; all [are] designed to lower intraocular pressure," says Dr. Morrison.
If medications don't work, then laser surgery to stimulate the part of the eye that drains fluid is often recommended. Conventional surgery to make new pathways so the fluid can drain more easily may be tried if other treatments are not effective.
"Many advances have been made in the past decade, and a lot of cutting-edge research is in progress," reports Dr. Mansberger. "In ten years, the way we test and treat glaucoma may be very different, with new ways to lower eye pressure and protect the optic nerve."
The good news is that treatments with high success rates are currently available for glaucoma. It's up to you to take the necessary steps to find out if you're at risk, or have the disease, so that you can pursue treatment to protect your vision and prevent blindness.